One technique for retaining ink in an ink chamber in an ink jet print head is to insert a compressed foam element into the ink chamber prior to filling the chamber with ink. The foam must be inserted into the chamber to a proper depth, generally to intimately contact a filter through which ink flows to reach the print head nozzles. The foam should be compressed against the internal walls of the ink chamber and, to the greatest extent possible, the corners of the chamber.
Therefore, the inserted foam should be wrinkle-free, without leaving corner voids, and inserted to the desired depth within the ink chamber.
One known way of inserting compressed foam into an ink chamber of an ink jet print head is to compress the foam within a compression device from which the foam is pushed into a thin walled tube. In a subsequent operation, the tube is inserted into the ink chamber and the foam extruded into the chamber by pushing the foam from behind as the tube is withdrawn.
It is an objective of the present invention to provide an improved method and apparatus for the insertion of compressed foam into an ink chamber of an ink jet print head.
This objective is met in accordance with one aspect of the present invention by the provision of a foam insertion tool which includes compression fingers. A foam element to be inserted into an ink chamber is compressed and pushed into an area within the compression fingers, which in turn are positioned within the ink chamber. A force applied to the foam first pushes the foam into the ink chamber and then the print head off of the compression fingers, with the foam being retained in the ink chamber.